1. Field of the Invention
The invention relates to a power transistor module, including a plastic frame used as the housing wall, a ceramic plate used as the housing bottom, structured metallizations on the housing bottom serving as conductor runs and terminal pads for one or more power transistors and bypass diodes, and wiring elements which are freely accessible from the top of the housing.
Such power transistor modules are generally known in the art.
2. Description of the Prior Art
Semiconductor components such as transistors which can be switched off, have shorter switching times than thyristors with forced quenching, and therefore permit higher switching frequencies. They can be employed to advantage in d-c control elements, d-c transformers, inverters and frequency converters for drives, and they permit the control of the energy flow between a nearly constant d-c voltage source and consumers with variable d-c and a-c voltage.
In order to drive power transistors, it is logical to provide an electrical connection to the collector terminal of the power transistor, as can be seen, for instance, from the publication by Lamboley, entitled "Intelligenter Baustein steuert and schutzt Leistungs-Transistor" (Intelligent Building Block Which Controls and Protects A Power Transistor), Elektronik 16, Aug. 13, 1982, pages 27 to 29, FIGS. 1 and 5. In the conventional case, an integrated module for monitoring and controlling the switching processes of the power transistor is employed. The use of such an integrated module is made difficult, however, because the auxiliary diode must still be incorporated in the integrated module as a discrete component between the terminals of the power transistor module.